Mechanisms of Inhaled Fine Particulate Air Pollution–Induced Arterial Blood Pressure Changes

Background Epidemiologic studies suggest a positive association between fine particulate matter and arterial blood pressure, but the results have been inconsistent. Objectives We investigated the effect of ambient particles on systemic hemodynamics during a 5-hr exposure to concentrated ambient air particles (CAPs) or filtered air (FA) in conscious canines. Methods Thirteen dogs were repeatedly exposed via permanent tracheostomy to CAPs (358.1 ± 306.7 μg/m3, mean ± SD) or FA in a crossover protocol (55 CAPs days, 63 FA days). Femoral artery blood pressure was monitored continuously via implanted telemetry devices. We measured baroreceptor reflex sensitivity before and after exposure in a subset of these experiments (n = 10 dogs, 19 CAPs days, 20 FA days). In additional experiments, we administered α-adrenergic blockade before exposure (n = 8 dogs, 16 CAPs days, 15 FA days). Blood pressure, heart rate, rate–pressure product, and baroreceptor reflex sensitivity responses were compared using linear mixed-effects models. Results CAPs exposure increased systolic blood pressure (2.7 ± 1.0 mmHg, p = 0.006), diastolic blood pressure (4.1 ± 0.8 mmHg; p < 0.001), mean arterial pressure (3.7 ± 0.8 mmHg; p < 0.001), heart rate (1.6 ± 0.5 bpm; p < 0.001), and rate–pressure product (539 ± 110 bpm × mmHg; p < 0.001), and decreased pulse pressure (−1.7 ± 0.7 mmHg, p = 0.02). These changes were accompanied by a 20 ± 6 msec/mmHg (p = 0.005) increase in baroreceptor reflex sensitivity after CAPs versus FA. After α-adrenergic blockade, responses to CAPs and FA no longer differed significantly. Conclusions Controlled exposure to ambient particles elevates arterial blood pressure. Increased peripheral vascular resistance may mediate these changes, whereas increased baroreceptor reflex sensitivity may compensate for particle-induced alterations in blood pressure.

[1]  C. Grupi,et al.  Effects of air pollution on blood pressure and heart rate variability: a panel study of vehicular traffic controllers in the city of São Paulo, Brazil. , 2005, European heart journal.

[2]  J. Manuel,et al.  Environews Spheres of Influence , 2003 .

[3]  A. D. Diez Roux,et al.  Associations between Recent Exposure to Ambient Fine Particulate Matter and Blood Pressure in the Multi-Ethnic Study of Atherosclerosis (MESA) , 2008, Environmental health perspectives.

[4]  Lars Barregard,et al.  Experimental Exposure to Wood-Smoke Particles in Healthy Humans: Effects on Markers of Inflammation, Coagulation, and Lipid Peroxidation , 2006, Inhalation toxicology.

[5]  D. Levy,et al.  Is the relation of systolic blood pressure to risk of cardiovascular disease continuous and graded, or are there critical values? , 2003, Hypertension.

[6]  M. Lippmann,et al.  Associations between Health Effects and Particulate Matter and Black Carbon in Subjects with Respiratory Disease , 2005, Environmental health perspectives.

[7]  R. Verrier,et al.  Technique for Implantation of Chronic Indwelling Aortic Access Catheters , 2006, Journal of investigative surgery : the official journal of the Academy of Surgical Research.

[8]  I. Adamson,et al.  Acute effects of inhaled urban particles and ozone: lung morphology, macrophage activity, and plasma endothelin-1. , 1998, The American journal of pathology.

[9]  G. Pickering,et al.  Reflex Regulation of Arterial Pressure during Sleep in Man: A Quantitative Method of Assessing Baroreflex Sensitivity , 1969, Circulation research.

[10]  G. A. Rooke,et al.  Work as a Correlate of Canine Left Ventricular Oxygen Consumption, and the Problem of Catecholamine Oxygen Wasting , 1982, Circulation research.

[11]  J. R. Koehler,et al.  Modern Applied Statistics with S-Plus. , 1996 .

[12]  G. Pickering,et al.  The reflex regulation of arterial pressure during sleep in man. , 1968, The Journal of physiology.

[13]  William N. Venables,et al.  Modern Applied Statistics with S-Plus. , 1996 .

[14]  J M Wolfson,et al.  Mechanisms of morbidity and mortality from exposure to ambient air particles. , 2000, Research report.

[15]  Jing-Shiang Hwang,et al.  Effects of Concentrated Ambient Particles on Heart Rate, Blood Pressure, and Cardiac Contractility in Spontaneously Hypertensive Rats , 2004, Inhalation toxicology.

[16]  J. Dartigues,et al.  Effects of particulate air pollution on systolic blood pressure: A population-based approach. , 2006, Environmental research.

[17]  G. Molenberghs.  Applied Longitudinal Analysis , 2005 .

[18]  J. Godleski,et al.  Permanent tracheostomy for long-term respiratory studies. , 2008, The Journal of surgical research.

[19]  Frances Silverman,et al.  Inhalation of Fine Particulate Air Pollution and Ozone Causes Acute Arterial Vasoconstriction in Healthy Adults , 2002, Circulation.

[20]  Annette Peters,et al.  Effects of air pollution on blood pressure: a population-based approach. , 2001, American journal of public health.

[21]  D. Goldstein.  Arterial baroreflex sensitivity, plasma catecholamines, and pressor responsiveness in essential hypertension. , 1983, Circulation.

[22]  Frances Silverman,et al.  Inhalation of Fine Particulate Air Pollution and Ozone Causes Acute Arterial Vasoconstriction in Healthy Adults , 2002 .

[23]  M. Shima,et al.  The Role of Intercellular Adhesion Molecule-1 (ICAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1), and Regulated on Activation, Normal T-Cell Expressed and Secreted (RANTES) in the Relationship between Air Pollution and Asthma among Children , 2001, Archives of environmental health.

[24]  B. Coull,et al.  Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs. , 2002, Environmental health perspectives.

[25]  H. Gong,et al.  Day-to-day particulate exposures and health changes in Los Angeles area residents with severe lung disease. , 1999, Journal of the Air & Waste Management Association.

[26]  R. Graham.  Selective alpha 1-adrenergic antagonists: therapeutically relevant antihypertensive agents. , 1984, The American journal of cardiology.

[27]  J. Kaufman,et al.  Fine Particulate Air Pollution and Cardiorespiratory Effects in the Elderly , 2005, Epidemiology.

[28]  Jing-Shiang Hwang,et al.  Effects of concentrated ambient particles on heart rate and blood pressure in pulmonary hypertensive rats. , 2002, Environmental health perspectives.

[29]  Annette Peters,et al.  Effects of particulate air pollution on blood pressure and heart rate in subjects with cardiovascular disease: a multicenter approach. , 2003, Environmental health perspectives.

[30]  J. Kaufman,et al.  Diesel Exhaust Inhalation Elicits Acute Vasoconstriction in Vivo , 2008, Environmental health perspectives.

[31]  P. Koutrakis,et al.  A technique to expose animals to concentrated fine ambient aerosols. , 1995, Environmental health perspectives.

[32]  J. Drazen,et al.  Experimental induction of chronic bronchitis in dogs: effects on airway obstruction and responsiveness. , 1982, The American review of respiratory disease.

[33]  P. Schwartz,et al.  Autonomic mechanisms and sudden death. New insights from analysis of baroreceptor reflexes in conscious dogs with and without a myocardial infarction. , 1988, Circulation.

[34]  P. Nafstad,et al.  Associations between environmental exposure and blood pressure among participants in the Oslo Health Study (HUBRO) , 2006, European Journal of Epidemiology.

[35]  J. Schwartz,et al.  DIABETES ENHANCES VULNERABILITY TO PARTICULATE AIR POLLUTION-ASSOCIATED IMPAIRMENT IN VASCULAR REACTIVITY AND ENDOTHELIAL FUNCTION , 2004, Circulation.

[36]  J. Samet,et al.  Air Pollution and Cardiovascular Disease: A Statement for Healthcare Professionals From the Expert Panel on Population and Prevention Science of the American Heart Association , 2004, Circulation.

[37]  Antonella Zanobetti,et al.  Ambient Pollution and Blood Pressure in Cardiac Rehabilitation Patients , 2004, Circulation.

[38]  V. Salomaa,et al.  Association of criteria pollutants with plasma hemostatic/inflammatory markers: a population-based study , 2005, Journal of Exposure Analysis and Environmental Epidemiology.

[39]  R. Brook,et al.  Acute Blood Pressure Responses in Healthy Adults During Controlled Air Pollution Exposures , 2005, Environmental health perspectives.

[40]  Karen R. Anderson,et al.  Day-to-Day Particulate Exposures and Health Changes in Los Angeles Area Residents with Severe Lung Disease. , 1999, Journal of the Air & Waste Management Association.